CXCR4 and metastasis: TB is often an under-recognized pathological factor in colorectal cancer, but its importance is underscored by studies showing that high-grade TB correlates with upregulation of negative regulatory immune checkpoints (PD-L1, TIM-3) and chemokine receptors (CXCR2, CXCR4) (28), which are associated with poor prognosis in patients with colorectal cancer liver metastasis undergoing neoadjuvant chemotherapy (29).